A through-silicon-via, or TSV, provides electrical continuity between the top and bottom surfaces of a semiconductor chip. A TSV is fabricated by deep etching into the silicon wafer, or substrate that comprises the semiconductor chip, and filling the resulting hole with a liner and a metal filling. The silicon substrate is then ground, or thinned, from the backside until the metal filling is exposed, and backside metal (BSM) is disposed on the thinned backside surface for electrical contact. This process is referred to as a backside thinning process. If the silicon is not etched deeply enough, the TSV may be defective. TSVs are useful in schemes such as 3D integration, where multiple chips may be vertically stacked upon one another. 3D integration is one of the ways increased circuit density is being achieved to enable smaller, yet more powerful electronic devices. It is therefore desirable to have improvements in the backside thinning process to improve yield and reliability.